The present disclosure relates to a rotary changer configured to replace a contact tip screwed on, and coupled to, a tip end of a torch body of a welding torch for use in arc welding.
A rotary changer for attaching or removing a contact tip to/from a tip end of a torch body of a welding torch for use in arc welding has been generally known in the pertinent art. For example, the rotary changer disclosed in Japanese Unexamined Patent Publication No. 2002-192345 includes a plurality of rotators for turning a contact tip on their center axis in order to perform such contact tip replacement work efficiently. Those rotators are horizontally arranged side by side in a rectangular parallelepiped housing holder such that their rotational axes are oriented vertically. A spur gear, of which the rotational axis is aligned with that of one of those rotators, is attached to the bottom of the rotator. A single drive motor with a vertically extending drive shaft is arranged under the housing holder, and a pinion gear facing inward under the housing holder is attached to the drive shaft. The housing holder is horizontally movable with a rack and pinion mechanism. Horizontally moving the housing holder transfers those rotators one after another to a tip replacement position where the contact tip is replaced with respect to the welding torch, and also allows the pinion gear to mesh with the spur gear of the rotator that has moved to reach the tip replacement position. This facilitates a change of the rotators at the tip replacement position where the contact tip is to be replaced, and also connects the rotator located at the tip replacement position to a driving part that turns the rotator, thereby rotating the rotator at the tip replacement position.
According to Japanese Unexamined Patent Publication No. 2002-192345, the spur gear of each of those rotators is allowed to mesh with the pinion gear attached to the drive shaft of the drive motor while being moved perpendicularly to its rotational axis. Therefore, repeated changes of the rotators at the tip replacement position would put a heavy load on the respective teeth of the spur and pinion gears in the tooth thickness direction every time the spur gear meshes with the pinion gear, thus eventually leading to deformation or damage of the spur and pinion gears.
The present disclosure provides a mechanism for substantially preventing, in a rotary changer including a plurality of rotators performing the contact tip replacement work and configured to rotate those rotators with a single drive source, a portion connecting each of those rotators to the drive source that drives the rotator from being deformed or damaged.